1. Technical Field
The present invention relates generally to a turbine engine and, more particularly, to a variable area vane arrangement for a turbine engine.
2. Background Information
A typical turbine engine includes a plurality of engine sections such as, for example, a fan section, a compressor section, a combustor section and a turbine section. One or more of the engine sections may include a variable area vane arrangement. Such a vane arrangement may be configured to guide and/or adjust flow of core gas between adjacent rotor stages within the respective engine section. Alternatively, the vane arrangement may be configured to guide and/or adjust flow of core gas between the respective engine section and an adjacent (e.g., downstream) engine section.
A typical variable area vane arrangement includes a plurality of rotatable stator vanes extending between an outer radial stator vane platform and an inner radial stator vane platform. Outer radial ends of the stator vanes are rotatably connected to the outer radial stator vane platform with an outer shaft and a bearing. Inner radial ends of the stator vanes are rotatably connected to the inner radial stator vane platform with an inner shaft and a bearing. The outer shaft may include a bore that directs cooling air from a plenum, adjacent the outer radial stator vane platform, into a cavity within an airfoil of the respective stator vane. Airfoil cooling apertures may subsequently direct the cooling air out of the cavity to film cool the outer surfaces of the airfoil that are exposed to the core gas. To provide a sufficient quantity of the cooling air, the outer shaft bore typically has a relatively large diameter. As the diameter of the outer shaft bore increases, however, the size of the bearing also increases, which may significantly increase the weight, cost and complexity of the vane arrangement.